EARLY TRANSISTOR HISTORY AT BELL LABS

An Interview with Homer Coonce

 Early Transistor Digital Logic - Flyable TRADIC to Nike Zeus

 

          

 

 

 

 

The module shown above is a “Circuit Pack” from the Flyable TRADIC computer – the module is approximately 2.5” X 1.5”, and is .375” in depth.   The connection of these circuit packs to the main computer interconnection “bus” was accomplished through the spring contacts on the rear of each circuit pack (photo shown at upper right). A variety of different circuits were developed for use in the TRADIC, including “OR” and “AND” gates.  Another circuit, shown to the right, is a “Transistor Amplifier”, using the 2N67 point contact transistor.  Note that the transistor is mounted in the circuit pack external to the pack housing. This was done so that a stream of cooled air could be directed over the transistor, to maintain a lower operating temperature for this fragile device and preventing a “lock-up” failure mode which resulted in the pulse transformer overheating and exploding. [2] [3]

 

 

 

 

 

 

 

 

 

 

 

 

 

Go To Coonce Oral History, Pg 6

 

 

 

 

 

COPYRIGHT © 2005 by Jack Ward.  All Rights Reserved.  http://www.transistormuseum.com/

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